Electric bell.



w. 1;. SMITH; 7 ELECTRIC BELL. APPLICATION mgn MAR-:13. 1913..

1911114 zoom:

Patented Feb. 20,-

UNITED. STATES ATENT OFFICE.

wmnmnm. SMITH, OF'NEW roan, N. Y., ASSIGNOZR. T0 nnwanns & eoiviremr, A

-- conronerron or NEW YORK. Y v

. ELECTRIC BELL.

, Specification of Letters Batent.

Application filed March 13,1 13. Seria1lNo.758,919.

To all whom it may concern! Be it known that I, WILLIAM J. SMITH, a citizen of the United States, residing at New York, in the borough of Manhattan and State of New York, have invented certain new and useful Improvements in Electric Bells, ofwhich thefollowing is a full, clear, and exact description.

This invention relates to improvements in electric bells, the main object of the invention' being to provide'a bell which will operate' successfully on an alternating current circuit. In the electromagnetic bells using alternating current it has been found to be difficult to construct a bell which will operate in rhythm with the cycles of alternating current and especially is this true where the bellis attached to an alternating current line of as higha. frequency as'isused for ordinary commercial purposes, which is generally of 60 cycles. I have found that by controlling the stroke of the hammer of an alternating current bell in a certain manner it will'operateas regularly on alternating current as on directand my invention consists essentially in positively limiting the backstroke ofv the hammer and also in limiting the back stroke'with relation to the action of the circuit interrupter. Another object of the invention is to construct a yielding connection between the hammer ,and

the armature which will also have the added function of preventing the armature from sticking. Other objects of the invention will be apparent from the specification and claims hereinafter set forth, wherein- Figure 1 is a sectional view of the bell, one of the coils of the electromagnet being removed;

Fig. 2 is an enlarged sectional detail view showing the hammer or fplunger in. contact with the bell; and

Fig. 3 is a view of that face of the armature which is adjacent the poles of the magnet and looking downward in Fig. 2, the hammer and bearings of the armature being in section.

Referring to the drawing, 1 represents a gong mounted on a post 2, which is supported on a base-plate 3 at one end thereof, the other end of the base-plate being attached to a casing 4 provided with a removable cover 5. The-end 7 of the casing is made separate from the main portion and has attached thereto the cores of the electromagnet 6,

the other end of these cores being joined together by means of a connecting plate 9 of brass or the like which is provided with lugs 10 bent at right angles to the,plateprovi'ded with openings through which the trunnions of the armature 11 pass, as clearly shown in Fig. 3. His a plate made of resilient material such as hardened copper, which plate is fastened to the armature by the rivet 18. The middle portion of the upper end of the plate is Patented Feb. 20,1917;

Attached to the armaturecut away as'at14 and the parts of the plate on each side of the same arebent to form cylindrical bearings 15 which support the pin '16, WhichiS fitted in an opening'in the reciprocating plunger or hammer 17," the other end of this hammer sliding through an opening in the end 7 of the casing provided for that purpose. The endsof the pin 16 are bent to prevent undue longitudinal movement thereof. The plate 12 has twoext ensions or arms 18- which are so positioned as to come in contact with the cores of the electromagnet when the 'armature'is'in its attracted position and so prevent the same from sticking. By making these arms integral with the resilient plate 12,"they aid in returning the spring-plate to its normal position against thearmature after-the same has been moved forward due to the inertia of the plunger 17 attached thereto. The armature ll'carries an-a'rm 19 which is fastened to but insulated from the same and carries at its free end'a carbon contact 20 which forms apart of the interrupter, here-- inafter referred to. The lower edge of the armature is provided with a lug through which aswiveledeye 21 passes. A spring 22 is connected at one end to the eye and at the other end is connected toa screw 23 whereby the tension of the springwhich holds the armature normally away carbon contact 24 of the interrupter. is carried on an arm 25 which is fastened to but insulated from the connecting plate 9. A set-screw 26 is inserted in the rear of the easing and acts as a back-stop to limit the rear-' ward travel of the reciprocating plunger 17. A similar set-screw is shown at 27 which is om'the 'electromagnet, may be regulated. A second provided with an insulated end and is used to draw said armature away of the reciprocating plunger or hammer that the period of vibration of the same will be in rhythm with the oscillations of alternating current used and produces an alternating current bell which strikes as regularly and continuously as if direct current were used. This stop 26 positively stops the hammer shortly after the circuit contacts have come together on the back stroke of the armature and. it has been found that the best operation of the bell depends somewhat upon the relative adjustment of the contacts and back stop. Current for the bell enters through the binding-post 28 from Which it passes through the coils of the electromagnet 6 to the insulated arm 25, contacts 24 and 20, arm 19, which is insulated from the armature, and out through a binding-post connected to the frame but insulated therefrom (not shown); Claims: I

1. An electromagnetic bell comprising an armature, a resilient plate attached thereto, a hammer connected with said plate, the inertia of the hammer moving the springplate away from the armature to permit the hammer tostrike the bell when the armature is moved to its attractedposition, said plate having at least one arm which engages with the core of the electromagnet when the armature is in its attracted position to prevent the same from sticking, said arm being resilient to .aid the spring-plate to return to its normalposition against the armature.

2. An electric bell comprising a casing, a gong carriedby said casing, an. electro-magnet in said casing, an armature for said electro-magnet, a spring exerting its tension from the core of the electro-magnet, a reclprocatory hammer having one end thereof projecting through an opening in said casing, the walls of said opening forming a bearing "for said hammer, an adjustable stop for limiting the rearward travel of. said hammer, an interrupter comprising a stationary contact, means for adjusting the position of said contact, a movable member carried by said armature, a plate mounted on said armature, a connection between said plate and said hammer, and said plate having a part of non-magnetic material interposed between of the electro-magnet, means rearward travel the core of the electro-magnet and its armature.

3. An electricbell comprising a casing, a gong carried by said casing, an electro-magnet in said casing, an armature for said electro-magnet, a spring exerting its tension to draw said armature away from the core for adjusting the tension of said spring, a reciprocatory hammer having one end thereof projecting through an opening in said casing, the walls of said opening forming a bearing for said hammer, an adjustable stop for limiting the rearward travel of said hammer, an interrupter comprising a stationary contact, means for adjusting the position of said contact, a movable member carried by said armature, a plate mounted on said armature, a connection between said plate and said hammer, and said plate having a part oi non-magnetic material interposed between the core of the electro-magnet and its armature. i

4. An electric bell comprising a casing, a gong carried by said casing, an electro-mag netin said casing, anarmature for said electro-magnet, a spring exerting its tension to draw said armature away from the core of the electro-magnet, a reciprocatory hammer having one end thereof projectin through an opening in said casing, the wa is of said opening forming a bearin for said hammer, an adjustable stop or limiting the of said hammer, an interrupter comprising a stationary contact, means for adjusting the position of said contact, a movable member carried by said armature, a plate mounted on said armature, a connection between said plate and hammer, said connection comprising a pin passing through said hammer and lugson said plate bent around the ends of said pin, and said plate having a part of non-magnetic material interposed between the core of the electro-magnet and its armature.

In witness whereof, I subscribe my signature, in the presence of two witnesses.

WILLIAM J. SMITH.

Witnesses R. EDWARDS, Jr,

CHRISTIAN MILLER. 

